Description

dbplus_find() will place a constraint on the
given relation. Further calls to functions like
dbplus_curr() or
dbplus_next() will only return tuples matching
the given constraints.

Constraints are triplets of strings containing of a domain name,
a comparison operator and a comparison value. The
constraints parameter array may consist of
a collection of string arrays, each of which contains a domain, an
operator and a value, or of a single string array containing a
multiple of three elements.

The comparison operator may be one of the following strings:
'==', '>', '>=', '<', '<=', '!=', '~' for a regular
expression match and 'BAND' or 'BOR' for bitwise operations.